a. Field of the Invention
This invention relates to retractable coverings for architectural openings, and more particularly, an operating system for controlling retractable coverings for architectural openings using a single operating element.
b. Background Art
Operating systems utilized in window coverings for architectural openings, such as shade and blind assemblies are commonly used. Conventional shade and blind assemblies typically comprise a head rail, bottom rail, and slats or a covering disposed therebetween. Generally, a control system for raising and lowering such blinds or shades are installed in the head rail and may include an operating element, such as a cord, for lowering or raising the blinds or shades. The operating element is typically connected to pulleys or drums within the head rail, which when activated by a user, lift the bottom rail or lower the bottom rail via cords attached to the bottom rail. The operating element may be a continuous loop so as to present to the user a convenient method for operating the shade or blind. Other control systems may have a plurality of operating elements that are not in a loop so as to present the user a choice of one of the operating elements to raise or lower the blind.
Whether the control system utilizes a single looped type operating element or a plurality of operating elements, the operator must choose which direction to pull the loop or which operating element to activate in order to move the architectural covering in a desired direction. This can be especially confusing if the operating elements are tangled. Inherent in the loop operating element system is the problem of having a very long operating element with which to operate the system. Often, a greater length of operating element is necessary to raise or lower the shade or blind due to the longer drop of the shade or blind. A greater length of the operating element or the use of a looped cord present a strangulation hazard to children who may become entangled in the operating element.